> The problem with light bulbs is that they get too hot and the heat is 
> concentrated in one spot; they also burn out quickly when used as heaters.

Rough service bulbs give less light and more heat and stand up best.

> Underneath the rack I have two 3' tubular heaters (135 watts each).

Always make sure that there is drainage so that the heaters do not get 
submerged in case of a meltdown or a spill.

This topic was extensively covered in the past.  Does anyone search and read 
the archives anymore?  I do, and find it a great resource.
Visit http://listserv.albany.edu:8080/cgi-bin/wa?S1=bee-l&D=1&T=0&H=0&O=D

allen
http://www.honeybeeworld.com/
---
One of the symptoms of an approaching nervous breakdown is the belief that 
one's work is terribly important. -- Bertrand Russell (1872-1970)
 

****************************************************
* General Information About BEE-L is available at: *
* http://www.honeybeeworld.com/bee-l/default.htm   *
****************************************************